Safety control mechanism switch



July 13, 1954 2,683,779

R. E. DISHMAN SAFETY CONTROL MECHANISM SWITCH Filed Feb. 10, 1950 6 Sheets-Sheet l R. E. DISH MAN SAFETY CONTROL MECHANISM SWITCH July 13, 1954 '6 Sheets-Sheet 2 INVENTOR. Q 0302 8w Filed Feb. 10, 1950 R. E. DISH MAN SAFETY CONTROL MECHANISM SWITCH July/13, 1954 6 Sheets-Sheet 3 Filed Feb. 10, 1950 m in "H 4 HHHU INVEN TOR.

A TTOR/VFY} lulylB, 1954 R. E. DISHMAN SAFETY CONTROL MECHANISM SWITCH 6 Shegts-Sheet 4 Filed Feb. 10, 1950 Q m\ dnb H m Q IN V EN TOR.

July 13, 1954 R. E. DISHMAN 2,683,779

SAFETY CONTROL MECHANISM SWITCH Filed Feb. 10, 1950 6 Sheets-Sheet 5 ifs-15 a I a 62 o a 14/ My :FI E- 1&

70 64 o i (55:5 65 I: 33662 4| i -o 6 7 a 4 INVENTOR. hf n 00 i 52.0% f) 6346/?WM6 d5 65 9 6/ BY R. E. DISHMAN SAFETY CONTROL MECHANISM SWITCH July 13, 1954 6 Sheets-Sheet 6 Filed Feb. 10, 1950 INVENTOR. 8w fiuj /iofmaw W BY 5 Patented July 13, 1954 UNITED STATES PATENT OFFICE 2 Claims.

My invention relates broadly to oil and gas well equipment, and more particularly to indicator, alarm and safety control mechanism for drilling rigs used in the petroleum industry.

One of the objects of my invention is to provide a construction of indicator for drilling rigs which represents in similitude the movement of the traveling blocks vertically through the drilling derrick for informing the draw-works operator on the ground of the approach of the traveling blocks with respect to the crown block in the derrick.

Another object of my invention is to provide a construction of visual indicator, electric alarm controller, and valve control mechanism for use in connection with the operation of oil and gas well derricks for indicating the approach of the traveling blocks of the derrick with respect to the crown block, sounding an alarm as the traveling blocks approach the ground block and/or actuating control mechanism for shutting down the draw-works under conditions of dangerous approach of the traveling blocks with respect to the crown block.

Another object of my invention is to provide an arrangement of indicator by which the drawworks operator of an oil and/or gas well derrick is visually informed at all times of the relative movement of the traveling blocks of the derrick with respect to the crown block of the derrick.

A still further object of my invention is to provide a construction of safety control mechanism for the traveling blocks of oil and/or gas well drilling rigs which is adjustable in accordance with the path of movement of the traveling blocks n of the drilling rig for effecting, at a selectively adjustable time, the shutting down of the drawworks under conditions where the traveling blocks may approach a predetermined limit.

Still another object of my invention is to provide a composite electrical circuit and valve operating mechanism controllable in timed relation to the movement of the traveling blocks of a derrick for controlling an electrical circuit closure and/or a valve actuator as the traveling blocks of the derrick move to a predetermined limit for preventing over-travel of the traveling blocks and movement of the blocks into an obstruction with the incident damage and injury which may result from such over-travel.

Still another object of my invention is to provide a precision type screw mechanism adjustable over a wide range of movement for reproducing in similitude the path of travel of the traveling blocks of an oil and/or gas well drilling rig and controlling by such simulated movement a countermechanism and electrical circuit and fluid valve control means for recording the travel of the traveling blocks and eiTecting a warning as the traveling blocks dangerously approach the crown block and automatically cutting off the movement of the traveling blocks under conditions of over-travel thereof, for eliminating danger which might result from collision of the traveling blocks with the crown block.

Other and further objects of my invention reside in the adjustable screw mechanism for an indicator and electrical circuit and valve control mechanism for the draw-works of oil and gas well drilling machinery, as set forth more fully in the specification hereinafter following by reference to the accompanying drawings, in which:

Figure l is a schematic view showing the application of the indicator, alarm and safety control mechanism to a drilling rig in accordance with my invention; Fig. 2 is a schematic horizontal sectional view taken substantially on line 22 of Fig. 1; Fig. 3 is a perspective view of the control mechanism of my invention; Fig. 4 shows the operating parts of the control mechanism illustrated in Fig. 3 in juxtaposed relation; Fig. 5 is a rear elevational view of the control mechanism shown in Fig. 3; Fig. 6 is an elevational view of the electrical switching mechanism which is operated by the control mechanism illustrated in Fig. 3, certain of the parts being broken away and illustrated in section; Fig. '7 is a fragmentary sectional view through the control valve which is operated by the mechanism illustrated in Fig. 6; Fig. 8 is a longitudinal sectional view through the control mechanism of my invention and showing the assembled relation thereof with the switching and valve operating mechanism of Figs. 6 and 7; Fig. 9 is a vertical sectional view taken substantially on line 9-9 of Fig. 8, the View being taken on an enlarged scale to more clearly show the coaction of the parts; Fig. 10 is a vertical sectional view taken substantially on line Ill-Ill of Fig. 8; Fig. 11 is a fragmentary view of the gearing associated with the control mechanism, the View being taken substantially on line lill of Fig. 8; Fig. 12 is a perspective view of the travelling nut employed in the control mechanism of my invention; Fig. 13 is a schematic view of the brake control mechanism employed in the system of my invention; Fig. 14 is a schematic diagrammatic view showing the electrical circuit for the alarm and the valve operating mechanism employed in the system of my invention; Fig. 15 is a vertical sectional view of the control mechanism of my invention associated with an indicator including a replica of the derrick with which the control mechanism of my invention is associated and Fig. 16 is an elevational view of the indicator shown in Fig. 15.

Mishaps which cause enormous amounts of property damage and fatal injuries to employees occur each year in the petroleum industry due to the driller or the operator allowing the traveling blocks to run into the crown blocks. One major oil company had two men killed and a large drilling contractor sustained $104,000 worth of property damage in such a mishap during 1949. There is a widespread need, therefore, for a device that will prevent these serious accidents.

There have been two devices developed; the first consisting of a photocell device and relays which set off an alarm, and the second consisting of a line that unspools from a spring loaded drum and goes up over the crown block and attaches to the traveling block. Both of these devices are expensive, cumbersome, and have not proved practical and have not been well received by the petroleum industry.

On some wells in the Gulf Coast area, heavy fogs are encountered and it is sometimes impossible for the driller to see more than a few feet up in the derrick. The attachment of my invention alloys the drilling crew to go in or come out of the hole regardless of fog.

My invention is directed to a simplified construction of indicator alarm control and valve control mechanism which may be readily installed adjacent the operators position at the draw-works of an oil and/or gas well drilling rig for visually reproducing in similitude the oil well derrick with which the draw-works is associated, and indicating the traveling blocks of the oil or gas well drilling rig and the relative movement thereof with respect to the crown block. The apparatus of my invention includes an electric alarm circuit which is operated to warm the operator of the dangerous approach of the traveling blocks with respect to the crown block of the drilling rig. The mechanism also includes valve control means which are operated automatical y for shutting oif the power, disengaging the clutch and applying the brake to the draw-works upon continued movement of the traveling blocks, by failure of the operator to respond to the warning signal theretofore sounded upon. the approach of the traveling blocks to the crown block.

Referring to the drawings in more detail, Fig. 1

pictorially shows my invention applied to the oil or gas well drilling rig. 40, with which there is associated the conventional draw-works 4| having cable winding drum l2 driven through drawworks drum shaft 33 from the conventional drawworks drive mechanism. not shown. The cable winding drum :22 controls the winding and unwinding of the cable 43 for raising and lowering the traveiing blocks represented generally at A attached to the rig indicated at at for controlling raising and lowering of the sections of the well casings or the manipulation of the drill bits. The traveling blocks are controlled by a multiplicity of cables 4-3 operating over multiple sheaves in the traveling blocks 44 and in the crown block 47.

The attachment of my invention is represented at 48 mounted adjacent the operators position of the draw-works 4i, and includes mechanism shown more particularly in Fig. 3 which is driven from shaft I, which is gear connected to the til) draw-works drum shaft 33. The shaft l carries a bevel gear la thereon which meshes with the bevel gear driving shaft represented at 2. I provide a mounting structure for the mechanism operated by bevel gear driving shaft 2, as shown more particularly in Fig. 9 wherein the bracket 49 is adjustably supported with respect to cylindrical housing 6. A pair of rails 53 connect at opposite ends 54 and 55 through bolts 50 with cylindrical housing 6. Plate 52 is attached to the frame of the draw-works 4| through connecting bolt 86 and is fastened to the guide rails 53 on the cylindrical housing 6. A linearly extending track member 23a connected with the rear of panel 23 is slidably supported between guide rails 53 associated therewith. Panel 23 is slidably keyed to the rails 53 by plates 5i connected to the rear of track member 23a. The cylindrical housing Bis screw-threaded at opposite ends thereof as represented at 2'!, for receiving the end cap carrying bearings 4 and I4, which form supporting means for the bearings 29 through which the bevel gear driving shaft 2 extends. Collar 28 is secured in position upon the projecting end of shaft 2 beyond the end cap 4 for generally maintaining shaft 2 in the proper relation to cylindrical housing 6 for presenting bevel gear 2a in meshing relation with bevel gear la. The bevel gear driving shaft 2 carries bevel gear 2a on the end thereof which is continuously urged into mesh with the bevel gear I a. of the drive shaft l by means of the coil spring 3 which continuously exerts a force against the end of the end cap and the rear of the bevel gear 2a. The bevel gear driving shaft 2 may thus be continuously driven so long as coil spring 3 maintains bevel gear 2a in mesh with bevel gear la.

The bevel gear driving shaft 2 is provided with a precision spiral screw designated at 30. This screw may be formed of four Acme threads per inch.

The screw drives a travel nut 5 which is engaged thereby, the traveling nut having a transverse projection thereon extending through a slot 25 in cylindrical housing 6,as shown more particularly in Fig. 3. The projection of the traveling nut 5 encounters in the course of its linear travel the angularly shiftable arm 1a of the counter mechanism 1. Counter mechanism 1 is a step by step device where arm la in its movement counterclockwise effects the shifting of one digit successively, but does not efleot movement of a digit on the return stroke of the mechanism as arm 1a moves in a clockwise direction. An arm indicated at I2 attached to the shaft 56 also projects in the path of the traveling nut 5 and when engaged thereby shifts the shaft 56 against the action of coil spring 3 which normally holds shaft 56 with its controlling electrical contacts thereon in an off position. The traveling nut 5 when contacting the arm I2 tends to shift arm l2 and shaft linearly, for moving th electrical contacts carried thereby in corresponding manner.

In an installation where shaft is long and on the rig on which it is installed, the hoisting drum shaft makes 90 revolutions in carrying the blocks from the lowest position up to .he point where the alarm is set to go off. "s means that traveling nut 5 travels axially for this particular rig, which I would say a typical medium depth drilling rig. On other rigs, this travel may only be about 18 inches while on others the travel may be about 30 inches in raising the blocks from the floor up to the derrickmans position.

The electrical contacts associated with shaft 56 are carried by housing 5! and are formed by spring pressed sets of contacts 58 and 59 and spring pressed sets of contacts 60 and 6! arranged in insulated relation one with respect to the other and adapted to be bridged by sections of insulation material l5 and IS on shaft 56 under all normal positions of the shaft 56. The spring means which effect the spring pressed operation of the sets of contacts are represented at H. Intermediate the insulated sections [5 and IS I provide a conductive section of the shaft indicated at 56a.

The housing 51 is provided with packing glands Ma and lab, in each end thereof, through which the shaft 56 is adapted to linearly slide. Coil spring 8 continuously exerts pressure between the flanged end 56?) of shaft 56 and the gland lea for maintaining shaft 55 in a position in which the shaft sections l5 and E6 of insulation material break the continuity of an electrical circuit through the sets of contacts 58-459 and Gil-5 l.

The assembly of the cylinder and the housing 51 will be more clearly understood by reference to Fig. 9 from which it will be seen that rear panel 23 supports the housing 51 and also extends beyond shaft 56 for substantially the en tire linear distance to which shaft 55 may be displaced, and forms by reason of horizontally extending slot H a guide for arm l9, which extends rearwardly with respect to arm l2 from adjustable sleeve and prevents angular shifting of shaft 56 so that movementthereof is confined in a linear path. Sleeve 29 is adjustable along shaft 56 by means of screw-threaded adjustment, represented at a. Thus, shaft 56 is free to be linearly displaced under control of traveling nut 5, but angular movement thereof is resisted.

The panel 23 carries two on and off control switches designated at 63 and 6 3, which are employed as test switches, as shown more particularly in the circuit diagram of Fig. 14. It will be realized that in an installation of the magnitude of the type involved in my invention, that it is necessary to determine from time to time whether the equipment is in a condition for operation under conditions of alarm and emergency. I accordingly provide switches 63 and 64, which, when manually moved to on position will accomplish the same results which are obtained upon the linear shifting of shaft 56.

The housing 57 provides a support for a quick opening air, hydraulic or steam valve, represented at 2!, with which there is associated the trip reset arm 22, pivotally mounted on the standard 85, which is erected on housing 5?. The standard 65 includes a horizontally extending fulcrum arm 66, to which is pivotally connected the cross-arm 67, pivoted at 67a. The lower end of cross-arm 67 connects as represented at $8 with the solenoid plunger shown at 65, which is operated by trip coil 2d. The upper end of crossarm 61 is provided with a notch for recess it? into which latch H, carried by trip reset arm 22, extends. The coil spring 12 extends between standard 65 and the end of cross-arm 6i and tends to maintain recess ill of cross-arm 6'! into engagement with latch 'i'i so long as trip reset arm 22 is maintained in a position holding valve actuating rod 69 downwardly in a position closing valve 2|. The valve actuating rod 69 is normally maintained in a vertically upward position by the action of coil spring 14 seated in valve housing 16 operating against flange 15 carried by valve actuating rod 13 raising valve 'l'l away from its coacting valve seat 18. When the trip reset arm 22 is maintained by engagement of the latch H with recess 10, the pressure of spring 14 is overcome, and valve 71 is maintained closed against valve seat 78. However, upon energization of solenoid M, cross-arm B1 is rocked to a position in which trip arm 22 is released with respect to the confining relation of latch TI and notch 10, so that coil spring 14 operates to raise valve 17, opening air, hydraulic or steam line 19 for supplying through pipe 36 pressure to the actuating cylinder 38. Actuating cylinder 38 cperates arm 31 connected with toggle mechanism 36 drawing brake band 34 into tight relation with respect to brake drum 8!. The brake shoes 82 carried by brake band 34, grip the surface of brake drum Bl, thereby bringing to a halt the movement of draw-works drum shaft 33. The brake drum 8! is secured on the shaft 33 of the draw-works, and constitutes the brake for the draw-works. Thus, valve 2| controls the stoppage of the draw-works. A hand reset lever 35 connects with the toggle mechanism 3 5 for releasing the brake band 34 with respect to the brake drum 8| when the draw-works are again placed in condition for operation.

The electrical circuit which controls the energization of the solenoid 24 is diagrammatically shown in Fig. 14 and operates the solenoid plunger 69 as heretofore described, which in turn operates the cross-arm 61, as heretofore described, and controls through the coaction of latch ll and recess Ill the movement of the trip reset arm 22 for correspondingly controlling valve 2| and the flow of pressure from inlet 79 to outlet 80, as schematically illustrated. Solenoid winding 24 is energized from suitable source of potential indicated at 83. The circuit is closed through contacts and El bridging the conductive shaft 56 when insulated section It thereof is displaced out of position between contacts 60 and 6!. As heretofore explained, on and off switch 64 is provided for test purposes so that a local test may be from time to time made, to be sure that the circuit through solenoid 24 is conditioned to prevent over-travel of the traveling blocks 44.

The alarm circuit includes the horn 0r annunciator 8 connected through source of potential with the set of contacts 58 and 59 bridged by shaft 56. The annunciator is not activated so long as the section of insulation material l5 separates contacts 58 and 59. However, when shaft 56 is shifted linearly to a position in which the conductive shaft 56 bridges contacts 58 and 59, the circuit is included from source of potential 85 through the annunciator or alarm 88, thereby sounding a warning signal to the operator that the traveling blocks d4 are approaching the crown block M. As heretofore explained, the on and off switch 63, when closed, will efiect excitation of the annunciator or alarm 84 for purposes of testing the system. Particular attention is called to the fact that the sections of insulation material l5 and I6 are of unequal length. This assures the excitation of the alarm circuit prior to the excitation of the circuit through solenoid 24. Thus, the operator will be adequately warned to take steps to shut down the draw-works manually upon initial sounding of the alarm. However, as the traveling nut 5 continue to advance under action of screw 38 and the operator has failed to take heed of the warning, insulated section It moves out from beneath contacts 6!] and BI,

7 whereby contacts Gland 61 are shunted by the metallic shaft 56, thereby energizing solenoid 24 and automatically effecting the shut down of the draw-works.

In addition to the braking operation which I have described, I also provide for the disengagement of the clutch in the draw-works simultaneously with the braking operation.

For derricks of different heights it is necessary that adjustment means beprovided for the proper positioning of the traveling nut 5. For this purpose the handwheel I3 is provided on the end of bevel gear driving shaft 2. The hand wheel l3 may be grasped and manually drawn backwards against the action of spring 3, disengaging bevel gear 2a from bevel gear la, after which traveling nut 5 may be shifted to any selected position by manual adjustment of shaft 2.

As heretofore explained in connection with Fig. 9, the entire cylinder 6 may be adjusted in position with respect to the housing 51 and the operating means associated therewith by linear adjustment of cylinder 6. The bracket 49 carried by cylinder 6, as heretofore explained, islinearly adjustable through plates 5| at the rear of the panel 23. The rails 53 are attachable to the draw-works through the stud and lock nut 86 extending from the rear of plate 52.

The operation of the indicator mechanism of my invention may be rendered even more convenient and effective to the operator by the addition of a supplementary indicator mounted in a vertical position, as illustrated in Figs. and 16 and which includes a vertically extending panel 81 of translucent material on which there is displayed the outline of the derrick with which the indicator is to coact, as represented at 88. Through the front of the panel 81 I provide a vertically extending slot 89 coincident with the vertical axis of the representation of" the derrick shown at 88. The movable indicator 90is vertically movable through the slot 89 and is carried by the arm 9| which projects rearwardly into the slotted cylinder 92. Slotted cylinder 92 is mounted in a vertical position and contains the mechanism similar to that describedin connection with cylinder 6. A shaft 93, having precision type Acme threads thereon, operates traveler nut 94, which connects with arm SI and indicator 90 to move indicator 90 up and downthe representation of the derrick 88 in similitude. Thus, the relative approach of the traveling block represented by the indicator 90 with respect to the top of the derrick representated pictorially at 95', may be visually observed. To facilitate such observation, electric light bulbs 96 and 91 are arranged behind the indicator screen 81; An arm 98, controlling contacts 99, is arranged in the path of movement of the arm 91, which effects a closing of the contacts 99 when the indicator approaches the end of its upward travel representing the approach of the traveling blocks with respect to the crown block, thereby sending an alarm. The position of contact arm 98 is vertically adjustable with respect to the path of movement of arm 9! for adjusting the position at which the alarm will be effective.

A similar adjustment is provided on the indicator attachment for setting the traveling nut 94. That is, a spring loaded notched clutch H10 is provided, which can be released so that the position of traveling nut 94 may be manually adjusted by revolving hand wheel I0] attached to shaft93 to allowv for the. proper locationof the contact arm 98 with respect to the path of movement of arm 9|.

A shaft leading to clutch I00 may be flexible, or the shaft can be a solid one provided with universal joints or panel gears in order to establish the connection with shaft 2 of the mechanism of my invention heretofore explained.

The indicator attachment is approximately 12" wide and 30" in heighth, and may be installedin a convenient place in front of the driller or operator, so that the operator can see the relative position of the traveling blocks as they approach the crown block at all times.

I have found the mechanism of my invention highly practical in its construction and operation. I realize that changes in detail of my invention may be made, and I desire that it be understood that no limitations upon my invention are intended other than may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. Limit control mechanism comprising supporting means, a pair of longitudinally extending fixed rails carried by said supporting means, a cylindrical casing carried by said rails and having a longitudinally extending slot therein opposite said rails, a panel structure, means adjustably mounting said panel structure for limited movement linearly of said rails, an electrical circuit controller mounted on said panel structure and extending longitudinally thereof and including an actuator extending adjacent said cylindrical casing, journalling means carried by each end of said cylindrical casing, a rotatable screw device extending axially of said casing and terminating short of the opposite interior ends thereof, a shaft extending from each end of said rotatable screw device and mounted in said journalling means in each end of said casing, a drive gear disposed adjacent one end of said casing, a gear member carried by one of said shafts and engageable with said drive gear, expansion spring means extending between the end of said casing and said gear member for normally urging said gear member into meshing relation with said gear means, an orientatable manual means carried by the other of said shafts and aligned axially with the aforementioned shaft for manually retracting said gear member out of meshing relation with said drive gear against the action of said expansion spring means and a movable member carried by said rotatable screw device and projecting through the longitudinal slot in said casing into the path of said actuator for operating said actuator, the position of said movable member being selectively adjustable on said rotatable screw device by revolving said rotatable screw device by said orientatable manual means while a longitudinal pull is exerted on said rotatable screw device for maintaining said gear member out of meshing relation with said drive gear.

2. Limit control mechanism comprising a casing having a longitudinally extending slot in one side thereof, journalling means in each end of said casing, a shaft extending longitudinally through said casing and journalled in each end thereof, a rotatable screw carried by said shaft and terminating short of each interior end of said casing, whereby said rotatable screw may be displaced axially through said casing in addition to the rotative movement thereof, an orientatable manual means on the externally projecting end of said shaft at one end of said casing, a bevel gear carried by the extremity of the other end of said shaft, expansion spring means concentrically disposed. over the last mentioned end of said shaft between said bevel gear and the exterior of the last mentioned end of said casing for urging said bevel gear continuously to a projected position, a drive gear normally meshing with said bevel gear in the projected position of said bevel gear under control of said expansion spring means, the orientatable manual means at the first mentioned end of said shaft being operative for retracting said bevel gear out of meshing relation with said drive means against the action of said expansion spring means and operative for selectively revolving said shaft while the bevel gear is maintained out of meshing relation with said drive means, a movable membcr carried by said rotatable screw and projecting through the slotted side of said casing and an electric circuit controller supported in longitudinally adjustable relation to the slotted side of said casing and disposed in the path of said movable member whereby said movable member establishes an actuating abutment with said electric circuit controller at a predetermined position along the path of travel of said movable member with respect to said screw, the position of said movable member on said screw being selectively settable from the end of said casing by manually revolving said rotatable screw throughout the period that said manual means maintains said bevel gear in retracted position out of meshing relation with said drive means.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 906,561 Reid Dec. 15, 1908 1,275,407 Dunn Aug. 13, 1918 1,461,207 Bonk July 10, 1923 1,966,249 Larson July 10, 1934 2,265,022 Bendz Dec. 2, 1941 2,578,358 Jellison Dec. 11, 1951 FOREIGN PATENTS Number Country Date 250,922 Great Britain Aug. 26, 1926 

